Send/Return for loopback?

[scheater5]

So, has anyone messed around with using the send and return to feed an effect into itself since the Helix routing won't let you do that?

I've been elbow-deep in synths and keyboards lately for my current gig, and so I'm thinking a lot about routing and sound design from a non-guitar perspective.  Got to pondering about how shimmer verb was invented - running a pitch shift into a 'verb and then piping the output back to the pitch shift.  That's essentially what the Plateaux setting is doing in a self-contained block.  But this kind of routing can do lots more than "shimmer verb" - relevant to me is that one of my favorite effects is the related-but-distinct "ice" or "crystal" delay (essentially the same concept with delay instead of verb - see also: strymon timeline and TC flashback 2).  While the internal routing can allow you to approximate this kind if thing if you devote an entire path to it, it can't create an infinite feedback*.  What WOULD work (I believe) is to insert a return before the blocks, and a send after them, and run a patch cable between them.  The bummer is that it creates an additional DA/AD conversion, but some signal degradation is not a big deal for the kinds of things I would use this for**.

So, my helix is already packed up for gigs this weekend - I could easily get it out and have a twiddle with some knobs, but I thought I'd toss this out to the community since I haven't seen anyone do this before - see if I could spark some ideas for others.  If I'm late to the party, feel free to point me towards the existing conversation - but I couldn't find any mention of this with a google search.  

*might be obvious, but word of warning - actual infinite feedback can damage speakers and hearing, depending on your setup.  I'd recommend keeping the volume low while experimenting - but hey, you do you.  Happy tweaking.  

**The helix's AD conversion is indeed awesome.  And you may well find some use for this I haven't envisioned.  YMMV.